Valves are used in various applications. For example, U.S. Pat. No. 9,566,397, issued Feb. 14, 2017, disclose a small-volume nebulizer with a one-way valve in the T component that facilitates airflow from a nebulizer to a patient during inhalation and seals the nebulizer output to stop airflow from the nebulizer during exhalation. The '397 Patent is incorporated herein by reference.